毒死蜱乳油对辣椒根围土壤细菌群落结构的影响

Effect of chlorpyrifos on bacterial community structure in pepper rhizosphere

摘要:

【目的】了解有机磷杀虫剂毒死蜱对土壤细菌群落结构的作用。【方法】联合微生物平板计数法、末端限制性片段多态性分析，选择PRIMER 5进行群落结构分析，以研究不同浓度的毒死蜱对辣椒根围可培养和不可培养细菌群落结构的影响。【结果】毒死蜱施入后前30 d，3个处理组的可培养细菌较对照组具有显著差异(P<0.05)，但在第30天后，处理组可培养细菌数均能恢复到对照水平。采用PRIMER 5对T-RFLP数据进行多角度分析发现，Hae Ⅲ酶切片段中，对照组C3、处理组Y0和Z2的细菌群落结构较整体聚类较远。HhaⅠ酶切片段中，150 μg/g的毒死蜱处理组(Z0)在第0天表现出最大的群落差异。ANOSIM表明，以不同浓度的毒死蜱分组，各组间细菌群落组成差异不显著(Hae Ⅲ：Global R=0.041，P=0.168；HhaⅠ：Global R=?0.04，P=0.842)；以不同取样时间分组时，细菌群落组成差异显著(Hae Ⅲ：Global R=0.304，P=0.001；HhaⅠ：Global R=0.28，P=0.001)。经SIMPER分析所有TRFs可知，对群落丰度贡献最大的片段分别为TRF239、TRF240、TRF241。在线比对得到其代表菌群有芽孢杆菌属(Bacillus sp.)、梭菌属(Clostridium sp.)、葡萄球菌属(Staphylococcus sp.)、八叠球菌属(Sarcina sp.)、假单胞菌属(Pseudomonas sp.)等。【结论】高浓度的毒死蜱会对土壤细菌群落产生影响，抑制根围细菌生长，从而遏制植物的健康生长，因而有必要及时采取措施以减少大量重复使用毒死蜱所带来的危害。

Abstract:

[Objective] To understand the effects of chlorpyrifos (CPF) on soil bacterial community structure. [Methods] Both cultivable and uncultured bacterial communities were studied by plate method and terminal restriction fragment length polymorphism (T-RFLP). PRIMER-E was used to analyze the data generated by T-RFLP. [Results] At the first 30 days, cultivable bacteria in CPF-treated group were significant different from the control group (P<0.05). The numbers of cultivable bacteria were recovered after the 30th day. Based on the analyzed of T-RFLP data by PRIMER-E, bacterial community was mostly changed (Hae III: C3 (the control group on 30th day), Y0 (the 15 μg/g CPF-treated group on the first day), Z2 (the 150 μg/g CPF-treated group on the 20th day); HhaⅠ: Z0 (the 150 μg/g CPF-treated group on the first day)). ANOSIM indicated that no significant differences were found between different chlorpyrifos concentrations (Hae Ⅲ: Global R=0.041, P=0.168; HhaⅠ: Global R=–0.04, P=0.842), while significant differences were found between different sampling time (Hae Ⅲ: Global R=0.304, P=0.001; HhaⅠ: Global R=0.28, P=0.001). TRF239, TRF240 and TRF241 made the largest contributions to community abundance. Several representative bacterial communities such as Bacillus sp., Clostridium sp., Staphylococcus sp., Sarcina sp., Pseudomonas sp. were achieved by online blasting. [Conclusion] High concentrations of chlorpyrifos will have a great disturbance on soil bacterial community, which will inhibit the growth of rhizosphere bacteria and may suppress the growth of plants. Thus we should reduce the harm caused by repeated use of chlorpyrifos in time.